CN108155182B

CN108155182B - Method for producing an optoelectronic semiconductor chip

Info

Publication number: CN108155182B
Application number: CN201810082618.5A
Authority: CN
Inventors: 布丽塔·格厄特茨; 约恩·斯托; 诺温·文马尔姆
Original assignee: Osram Opto Semiconductors GmbH
Current assignee: Ams Osram International GmbH
Priority date: 2013-08-21
Filing date: 2014-08-08
Publication date: 2022-01-07
Anticipated expiration: 2034-08-08
Also published as: US9876001B2; CN105474415B; US20170194305A1; US9985011B2; CN108155182A; WO2015024801A1; DE102013109031A1; DE102013109031B4; JP6212642B2; US20160190110A1; CN105474415A; KR20160045085A; KR102315576B1; JP2016532295A

Abstract

A method for producing an optoelectronic semiconductor chip is proposed, which comprises the following steps: -providing a semiconductor body (1) with a pixel region (2) having at least two different sub-pixel regions (3), -applying a conductive layer (18) onto a radiation exit face (9) of at least one sub-pixel region (3), wherein the conductive layer (18) is adapted to at least partially constitute a salt with reaction partners of protons, -depositing a conversion layer (19, 19') on the conductive layer (18) by an electrophoretic process.

Description

Method for producing an optoelectronic semiconductor chip

The present invention application is a divisional application of an invention patent application having an application number of 201480046508.3 (international application number of PCT/EP2014/067098) and an invention name of "a method for manufacturing an optoelectronic semiconductor chip", which was filed on 8/2014.

Technical Field

The invention relates to a method for producing an optoelectronic semiconductor chip.

Background

In particular, in the method, the conversion layer is electrophoretically deposited on the semiconductor body. Methods for applying the conversion layer are described, for example, in the documents c.r.belton et al, j.phys.d.: appl.phys.41, 094006 (2008).

Disclosure of Invention

A method should be proposed, with which it is possible to: the conversion layer is applied to a relatively small sub-pixel area to produce different colors.

This object is achieved by having a method according to an embodiment of the invention. Advantageous further developments and embodiments of the method are the subject matter of the examples of the invention.

In a method for producing a semiconductor chip, a semiconductor body having a pixel region is provided. The pixel region has at least two different sub-pixel regions. Preferably, the sub-pixel regions are configured to be electrically insulated from each other. Each sub-pixel region preferably has an active layer adapted to emit electromagnetic radiation in a first wavelength range during operation of the semiconductor body. It is particularly preferred that the first wavelength range has or is formed by blue light.

The sub-pixel areas have, for example, a side length of up to 150 micrometers. The sub-pixel regions can be separated from each other by trenches, for example. For example, the sub-pixel regions are arranged at a certain distance from each other. For example, the spacing between two immediately adjacent sub-pixel regions has a value of no more than 10 microns.

Furthermore, a conductive layer is applied to the radiation exit face of at least one sub-pixel region. The electrically conductive layer is adapted to at least partially constitute a salt with the proton-reactive participants.

Particularly preferably, the conductive layer has or is formed from a metal, a metal alloy, a semi-metal or a semiconductor material. For example, the conductive layer can have or be formed from one of the following materials: lithium, sodium, potassium, rubidium, cesium, beryllium, calcium, magnesium, strontium, barium, scandium, titanium, aluminum, silicon, gallium, tin, zirconium, zinc oxide, zinc sulfide, zinc selenide, zinc telluride, and tin oxide.

The electrically conductive layer particularly preferably has a thickness of between 20 nm and 20 μm, including the boundary values. For example, the conductive layer has a thickness between 20 nanometers and 300 nanometers, inclusive. Particularly preferably, the conductive layer has a thickness of between 20 nm and 100 nm, including the boundary values.

Preferably, the conductive layer has a conductivity of at least 1 Siemens/Meter (Siemens/Meter). The conductivity of the conductive layer can also be increased by doping. This conductivity advantageously also enables sufficient charge transport in a relatively thin conductive layer, which approximately has a thickness of between 20 nm and 300 nm or between 20 nm and 100 nm, including the boundary values.

The conductive layer can be deposited, for example, by thermal evaporation or sputtering.

A conversion layer is deposited on the conductive layer by an electrophoretic process. The conversion layer is adapted to convert electromagnetic radiation of a first wavelength range into radiation of a second wavelength range. In other words, the conversion layer is formed in a wavelength-converting manner.

Currently, the term "wavelength conversion" refers in particular to: the incident electromagnetic radiation of a specific wavelength range is converted into electromagnetic radiation of another, preferably longer, wavelength range. In general, the wavelength conversion element absorbs electromagnetic radiation of the wavelength range which is injected, which is converted into electromagnetic radiation of other wavelength ranges by electronic processes at the atomic level and/or molecular level and emits the converted electromagnetic radiation again.

The conversion layer generally comprises particles of a luminescent material, which particles impart a wavelength-converting property to the conversion layer.

For example, one of the following materials is suitable for the phosphor particles: rare earth doped garnets, rare earth doped alkaline earth metal sulfides, rare earth doped thiogallates, rare earth doped aluminates, rare earth doped silicates, rare earth doped orthosilicates, rare earth doped silicon chlorosilicates, rare earth doped alkaline earth metal silicon nitrides, rare earth doped oxynitrides, rare earth doped aluminum oxynitrides, rare earth doped silicon nitrides, rare earth doped sialon (Sialone, sialon polymeric material).

In the present method, it is particularly preferred to use relatively small luminescent material particles in order to coat relatively small sub-pixel regions. Particularly preferably, the diameter of the phosphor particles does not exceed a value of 5 μm.

In an electrophoretic process, particles to be applied, for example of a luminescent material, are accelerated by means of an electric field, so that a layer of the particles is deposited on the surface provided. The surface to be coated is usually provided in an electrophoresis tank which contains particles which are provided for forming the conversion layer. In an electrophoretic process, particles are deposited only on a portion of a surface that is configured to be electrically conductive. Different particle deposition typically occurs depending on the conductivity of the region.

The idea of the invention is that: the conductive layer is applied to the surface to be coated and thus always provides the same surface for electrophoretic deposition.

A method for depositing an electrophoretic layer is described, for example, in document DE 102012105691.9, the disclosure of which is incorporated herein by reference.

In a particularly preferred embodiment of the method, the conductive layer is substantially chemically inert with respect to the organic solvent of the electrophoretic bath. The term "chemically inert" is used herein to denote: the conductive layer does not undergo significant chemical reaction with the organic solvent, wherein minor chemical reactions between the two materials cannot generally be completely ruled out in practice.

For example, the electrophoresis tank contains, as an organic solvent, one of the following materials: ethanol, acetone, aromatic hydrocarbon and acetaldehyde.

According to one embodiment of the method, the phosphor particles of the conversion layer produced by means of electrophoresis are fixed by means of an adhesive after the electrophoresis method. The adhesive can be, for example, silicone or epoxy or a mixture of said materials. Other suitable materials or coatings can also be used as the adhesive.

According to one embodiment, each sub-pixel region has a radiation exit surface which is electrically conductive. For example, the radiation exit area of each subpixel area is formed by a transparent conductive layer. The transparent conductive layer is particularly preferably formed by a TCO material ("TCO" denotes a transparent conductive oxide) or has a TCO material.

The transparent conductive oxide is typically a metal oxide such as zinc oxide, tin oxide, cadmium oxide, titanium oxide, indium oxide, or Indium Tin Oxide (ITO). Other than binary metal oxides, e.g. ZnO, SnO₂Or In₂O₃In addition to ternary metal oxides, e.g. Zn₂SnO₄、ZnSnO₃、MgIn₂O₄、GaInO₃、Zn₂In₂O₅Or In₄Sn₃O₁₂Or mixtures of different transparent conductive oxides, also belong to the TCO group. Furthermore, the TCO corresponds optionally to the stoichiometric composition and can also be p-doped as well as n-doped.

The conductive layer is now applied to the radiation exit face of at least one sub-pixel region, wherein the radiation exit faces of the other sub-pixel regions are free of the conductive layer.

According to one embodiment of the method, in the electrophoretic deposition of the conversion layer, the sub-pixel region on which the conversion layer is applied is energized independently of the other sub-pixel regions. In this way, the conversion layer can be applied only locally on the sub-pixel region being energized, while the remaining sub-pixel regions not loaded with current remain free of conversion layer.

The semiconductor body can be provided particularly simply with a conversion layer and particularly different sub-pixel regions can be provided particularly simply with different conversion layers if the sub-pixel regions can be individually energized at the time of deposition of the conversion layer and their radiation exit areas are made electrically conductive.

If the radiation exit area of each sub-pixel region is electrically conductive and it is not possible or only very difficult to individually load the sub-pixel regions with current, then according to a further embodiment of the method, the conductive layer is applied over its entire surface to the front side of the semiconductor body. Subsequently, on the conductive layer, a photoresist layer is applied in at least one sub-pixel area, while the conductive layer is freely accessible in another sub-pixel area. Next, an electrophoretic process is carried out and the conversion layer is usually deposited over its entire surface. For this purpose, the conductive layers are preferably in each case electrically contacted laterally. Since the photoresist layer has an electrically insulating surface, the phosphor particles are deposited only on freely accessible regions of the electrically conductive layer during the electrophoresis process. After the electrophoresis process is finished, the photoresist layer is removed again.

It is then possible to reapply the photoresist layer and to expose the conductive layer of the other sub-pixel regions. Then, in a subsequent electrophoretic process, a further switching layer is deposited on the freely accessible electrical layer. The further conversion layer is preferably suitable here for converting electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range which is different from the first and second wavelength ranges.

Furthermore, it is also possible for the surface of the sub-pixel region of the semiconductor body to be formed first by means of a passivation layer. The passivation layer is electrically insulating and is provided to protect the semiconductor body from external influences, for example. For example, the passivation layer is formed from an oxide or a nitride or has one of the materials. Usually, the passivation layer is applied over the entire surface of the front side of the semiconductor body. The front side of the semiconductor body comprises the radiation exit area of the sub-pixel region.

According to one embodiment of the method, the electrically conductive radiation exit face is produced by removing a passivation layer applied on the sub-pixel region.

Furthermore, it is also feasible for the passivation layer to remain on the front side of the semiconductor body and on the radiation exit face of the sub-pixel region. In the described embodiment of the method, the entire surface of the conductive layer is applied to the front side of the semiconductor body. In a next step, a photoresist layer is applied to the conductive layer in at least one sub-pixel region, while the conductive layer is freely accessible in the other sub-pixel regions.

Particularly preferably, the entire applied conductive layer is electrically contacted laterally during the electrophoretic process.

If a semiconductor body is provided in which the radiation exit face of each sub-pixel region is formed by a passivation layer, the passivation layer can also be removed from the radiation exit face of the sub-pixel region, so that the radiation exit face is constructed to be electrically conductive, while the passivation layer remains on the radiation exit face of at least one sub-pixel region. The conductive layer is then applied to the conductive radiation exit face, while the radiation exit face of the sub-pixel region formed by the passivation remains free of the conductive layer. The conversion layer is then applied to the conductive layer by means of an electrophoretic process.

The conversion layer is applied only to the regions from which the passivation has been removed beforehand, the remaining surface being free of the conversion layer, since said surface is not electrically conductive.

Preferably, in the described embodiment of the method, the steps described in the preceding paragraph for applying a further conversion layer to a further sub-pixel region are repeated. For this purpose, the passivation layer is removed in the region of the radiation exit face of the further subpixel region and a conductive layer is applied to this exposed region. A further conversion layer is then applied to the conductive layer by means of a further electrophoretic process. The further conversion layer is suitable for converting electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range which is different from the first and second wavelength ranges.

Preferably, each pixel region has exactly three sub-pixel regions. For example one of the three sub-pixel areas is arranged to emit green light while the other sub-pixel area is arranged to generate red light and the third sub-pixel area should emit blue light. If, for example, the first wavelength range has blue light, it is particularly preferred that no conversion layer is present in this one sub-pixel region. The further sub-pixel region preferably has a conversion layer which is suitable for converting electromagnetic radiation of a first blue wavelength range into electromagnetic radiation of a second wavelength range, wherein the second wavelength range preferably has or consists of green light. The third subpixel area preferably has a further conversion layer which is suitable for converting blue radiation of the first wavelength range into radiation of a third wavelength range, preferably having or consisting of red light.

The conversion layer is particularly preferably designed in such a way that it converts the radiation of the first wavelength range into radiation of the second wavelength range or of the third wavelength range as completely as possible.

According to one embodiment of the method, the electrically conductive layer is introduced into the reaction partners of the protons after the electrophoresis process, so that the electrically conductive layer at least partially forms a salt with the reaction partners of the protons. This provides the advantages of: the conductive layer, which is at least partially converted to a salt, is generally better permeable to visible light than the conductive layer itself. If a conductive layer is thus applied on the radiation exit face, it only slightly hinders coupling out of light from the radiation exit face after conversion into salt. Furthermore, it is also possible for the salt to be washed out again from the finished component as completely as possible.

According to one embodiment of the method, the salt is at least partially washed out of the semiconductor chip. The salt is particularly preferably removed from the surface of the semiconductor chip.

The reaction partner of the material M of the electrically conductive layer with the protons of the general formula ROH is generally reacted as follows:

M+ROH→M(OR)+H₂

if the electrically conductive layer has aluminum, for example, the aluminum forms a salt with water as a reaction partner for the protons as follows:

2Al+6H₂O→2Al(OH)₃+2H₂

the reaction partner of the protons in water can be present here as a liquid or in the gaseous state as water vapor.

Alternatively, hydrochloric acid, for example, can also be used as a reaction partner for protons for the aluminum-containing conductive layer. The salt formation will for example proceed according to the following formula:

Al+HCl→AlCl₃+H₂

if the electrically conductive layer has sodium, for example, sodium and water as a reaction partner for the protons typically form a salt as follows:

2Na+4H₂O→2Na(OH)₂+2H₂

if the electrically conductive layer has, for example, silicon, the salt of silicon with hydrochloric acid as a reaction partner for protons is generally formed as follows:

Si+3HCl→HSiCl₃+H₂

the chemical reaction between the material of the electrically conductive layer and the reaction partners of the protons can generally be accelerated advantageously by adding an alkali or alkaline solution. Furthermore, the chemical reaction between the material of the electrically conductive layer and the reaction partner of the protons can take place directly in the reaction partner of the protons or, however, also in the aprotic solvent to which the reaction partner of the protons is added in a corresponding amount.

According to one embodiment of the method, the reaction partner of the protons is contained in or present as a liquid or as a gas.

For example, the reaction partner of the proton is water, ethanol, carboxylic acid, mineral acid, amine, amide or a mixture of at least two of these materials.

The electrophoretically applied conversion layer can have pores through which the reaction partners of the protons in gaseous or liquid form and also the solvent can pass to the electrically conductive layer or the salt formed to wash off the salt. In this way, a chemical reaction between the reaction partner of the protons and the electrically conductive layer can be carried out. In addition, the salts formed can also diffuse into the solvent to be washed out.

Drawings

Further advantageous embodiments and further developments of the invention emerge from the exemplary embodiment described below with reference to the drawings.

Fig. 1 and 2 each show a schematic cross-sectional view of a semiconductor body according to a respective embodiment, as can be provided in the method described here.

The schematic sectional views according to fig. 3 to 9 illustrate the method according to the first embodiment.

The schematic sectional views according to fig. 10 and 11 illustrate the method according to the second embodiment.

The schematic sectional views according to fig. 12 to 19 illustrate a method according to a third embodiment.

Identical, homogeneous or functionally equivalent elements are provided with the same reference symbols in the figures. The drawings and the proportional relationship of elements shown in the drawings to one another are not to be considered to be to scale. Rather, the individual elements, in particular the layer thicknesses, can be exaggerated for a better illustration and/or for a better understanding.

Detailed Description

The semiconductor body 1 according to the embodiment of fig. 1 has a pixel region 2 with three sub-pixel regions 3. Each sub-pixel region 3 has a semiconductor layer sequence 4 with an active layer 5 which is suitable for generating electromagnetic radiation in a first wavelength range. Currently, the active layer 5 is adapted to generate visible blue light. Each two directly adjacent sub-pixel regions 3 are separated from each other by a trench 6. In this case, the trenches 6 each completely cut through the active layer 5. In addition, the trench 6 now completely separates the semiconductor layer sequence 4. In this way, the semiconductor layer sequence 4 of each sub-pixel region 3 constitutes a projection.

Furthermore, the semiconductor body 1 comprises a carrier element 7 on which the pixel regions 2 are arranged. A reflective layer 8 is arranged between the carrier element 7 and the semiconductor layer sequence 4. The reflective layer 8 is adapted to reflect electromagnetic radiation generated in the active layer 5 with respect to a radiation exit face 9 of the sub-pixel area 3. Furthermore, the reflective layer 8 is electrically conductive, so that each sub-pixel region 3 can be electrically contacted on the rear side via the carrier element 7. The carrier element 7 can be, for example, an active matrix element of a display.

A passivation layer 10 is applied on the side of the semiconductor layer sequence 4. The passivation layer 10 now completely covers the side faces of the semiconductor layer sequence 4. Furthermore, a passivation layer 10 is also formed in the trench 6 between the respective adjacent sub-pixel regions 3. The passivation layer 10 extends from the radiation exit area 9 on the side of the semiconductor layer sequence 4 up to the radiation exit area 9 thereof via the trench 6 and the side of the adjacent sub-pixel region 3. However, the front side of the semiconductor layer sequence 4 of each sub-pixel region 3 facing the radiation exit face 9 is free of the passivation layer 10.

An electrically insulating region 11 is provided on a main surface of the carrier element 7 facing the semiconductor layer sequence 4. Electrically insulating regions 11 extend along the main surface between two directly adjacent sub-pixel regions 3, and each have a recess 12 in the region of the sub-pixel region 3, which is filled with the electrically conductive material of the carrier element 7. The electrically insulating regions 11 of the carrier element 7 cooperate with the passivation layer 10 on the side of the sub-pixel regions 3 and in the trenches 6, so that the sub-pixel regions 3 are electrically insulated from one another, respectively. The sub-pixel regions 3 are electrically contacted at the rear side by the empty spaces 12 between the electrically insulating regions 11.

Furthermore, the sub-pixel region 3 has a transparent conductive layer 13 on its radiation exit face 9, via which the sub-pixel region 3 is electrically contacted on the front side. The transparent conductive layer 13 is applied over the entire surface of the front side of the pixel region 2, which front side comprises the radiation exit surface 9 of the sub-pixel region 3. The transparent conductive layer 13 in this embodiment completely covers the radiation exit face 9 of the sub-pixel region 3 and the side faces of the sub-pixel region 3.

On the transparent conductive layer 13, in each case a metal conductor track 14 is additionally applied in the trenches 6 between the sub-pixel regions 3, said conductor tracks serving for external contacting of the sub-pixel regions 3.

In this regard, it should be noted that: although in the figures each only a pixel region 2 with three sub-pixel regions 3 is shown by way of example, the semiconductor body 1 usually has a plurality of such pixel regions 2. In this case, the pixel regions 2 are particularly preferably all of the same type.

The semiconductor body 1 according to the exemplary embodiment of fig. 2 likewise has a pixel region 2 with three different sub-pixel regions 3. Each sub-pixel region 3 has a semiconductor sequence 4 with an active layer 5 which is adapted to emit electromagnetic radiation of a first wavelength range, preferably blue light. The sub-pixel regions 3 are again separated from one another by trenches 6, the trenches 6 passing completely through the active layer 5 and also the semiconductor layer sequence 4. As already described above, the semiconductor body 1 in turn comprises a carrier element 7. The carrier element 7 is designed, for example, as an active base element. Such an active matrix element is for example provided with silicon or is formed from silicon.

Between the carrier element 7 and the active semiconductor layer sequence 4, as in the exemplary embodiment of fig. 1, a reflective layer 8 is applied, which is electrically conductive.

Unlike the semiconductor body 1 according to the exemplary embodiment of fig. 1, however, the passivation layer 10 is formed over the entire surface on the front side of the semiconductor body 1 according to the exemplary embodiment of fig. 2. Here, the passivation layer 10 is formed of an electrically insulating material, such as an oxide or nitride. The passivation layer 10 now completely covers the radiation exit face 9 of each sub-pixel region 3, the side faces of each sub-pixel region 3 and the bottom of the trench 6 between the sub-pixel regions 3.

Since the radiation exit area 9 of the sub-pixel region 3 is formed in the semiconductor body 1 according to the exemplary embodiment of fig. 2 by the electrically insulating material of the passivation layer 10, the sub-pixel region 3 cannot be electrically contacted via its radiation exit area 9. For this reason, a further metallic conductive layer 8' with vias 15 through the active layer 5 is applied between the carrier element 7 and the reflective layer 8. The vias 15 serve to electrically contact the semiconductor layer sequence 4 on the front side. The further metal layer 8' and the via 15 are separated by the reflective layer 8, the active layer 5 and the region of the semiconductor layer sequence 4 facing the carrier element 7 by means of an electrically insulating layer 16.

In the method according to the first embodiment of fig. 3 to 9, a semiconductor body 1 is provided, as already described in detail with reference to fig. 1. A photoresist layer 17 is applied over the entire surface of the front side of the semiconductor body 1 (fig. 3). By the photolithographic structuring of the photoresist layer 17, the radiation exit faces 9 of the two sub-pixel regions 3 are exposed, while the radiation exit face 9 of the third sub-pixel region 3 is completely covered by the photoresist layer 17. The trench 6 between the two exposed sub-pixel regions 3 is also filled with a photoresist layer 17 (fig. 4).

In a next step, the conductive layer 18 is applied over the entire surface over the front side of the semiconductor body 1 (fig. 5). The electrically conductive layer 18 is adapted to at least partially constitute a salt with the reaction partners of the protons.

In a next step, the structured photoresist layer 17 is removed, which step is schematically illustrated in fig. 6. Now, a conductive layer 18 is present on the freely accessible radiation exit face 9 of the sub-pixel region 3. Whereas the radiation exit face 9 of the sub-pixel region 3, which is covered with the photoresist layer 17, is freely accessible. The trench 6 between the side of the semiconductor layer sequence 4 and the sub-pixel region 3 is also free of the conductive layer 18. In other words, the radiation exit faces 9 of the two sub-pixel regions 3 are covered with the conductive layer 18 only, while the remaining front side of the pixel region 2 is free of the conductive layer 18.

In a next step, a conversion layer 19 is deposited on the conductive layer 18 of the sub-pixel region 3 by means of an electrophoretic process (fig. 7). The conversion layer 19 is suitable here for converting electromagnetic radiation of a first wavelength range into electromagnetic radiation of a second wavelength range. Where the second wavelength range is formed by green light. The conversion layer 19 is designed in such a way that it converts the electromagnetic radiation emerging from the radiation exit area 9 of the sub-pixel region 3 into green light as completely as possible.

During the electrophoretic deposition of the conversion layer 19, the sub-pixel regions 3 on which the conversion layer 19 is to be applied are only loaded with current. Thus, in the electrophoretic process, the luminescent material particles are accumulated only on the sub-pixel regions 3.

In a next step, a further conversion layer 19' is then applied to a further sub-pixel region 3, the radiation exit face 9 of which is covered with the electrically conductive layer 18 (fig. 8). The further conversion layer 19' is adapted to convert electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range, which is different from the first and second wavelength ranges. It is particularly preferred that the further conversion layer 19' is adapted to convert the blue light generated in the active layer into red light as completely as possible.

In a next step, the material of the electrically conductive layer is stripped off in such a way that at least the electrically conductive layer is introduced into the reaction partners of the protons, so that the electrically conductive layer at least partially forms a salt with the reaction partners of the protons. In a further step, the formed salt is washed out of the semiconductor chip (fig. 9). In particular, the salt is removed from the surface of the semiconductor chip 1 by rinsing.

In the method according to fig. 3 to 9, a semiconductor body 1 is used, the sub-pixel regions 3 of which can be individually loaded with current. It is therefore possible for the individual sub-pixel regions 3 to be loaded with current in an electrophoretic process and thus to deposit the conversion layers 19, 19' only on the sub-pixel regions 3 loaded with current. If it is not possible or not desirable for the sub-pixel regions 3 to be loaded with current alone, the regions of the front side of the semiconductor body 1 which are not to be provided with the conversion layers 19, 19 'are covered with a photoresist layer 17 before the electrophoretic deposition of the conversion layers 19, 19', respectively. During the electrophoretic process, only the region to be coated on the front side of the semiconductor body 1 remains freely accessible.

In the method according to fig. 10 and 11, the semiconductor body 1 is provided in a first step, as already described in detail with reference to fig. 2 (fig. 10). In a next step, the passivation layer 10 is removed from the radiation exit face 9 of the sub-pixel region 3 by means of photolithography. In this way, the radiation exit face 9 of the sub-pixel region 3 is electrically conductive (fig. 11). If the sub-pixel regions 3 can be individually energized, two different conversion layers 19, 19 'are now applied to the electrically conductive radiation exit area 9 of the second sub-pixel region 3, as has already been described in detail with reference to fig. 3 to 9, while the radiation exit area 9 of the sub-pixel region 3 is free of the conversion layers 19, 19' (not shown).

If it is not possible to apply the current to the sub-pixel regions 3 individually, only the sub-pixel regions to be coated are exposed selectively in turn and conversion layers 19, 19' (not shown) are provided in each case corresponding to the method according to fig. 3 to 9.

In the method according to fig. 12 to 19, a semiconductor body 1 is likewise provided, as already described in detail according to fig. 2 (see fig. 12). In the case of the semiconductor body 1 described, the conversion layer 10 should, of course, remain completely on the semiconductor body 1, in contrast to the methods according to fig. 10 and 11.

In a first step, a conductive layer 18 is applied over the entire surface of the front side of the radiation exit area 9 of the semiconductor body 1, including the sub-pixel regions 3, said conductive layer being suitable for forming a salt at least in part with the reaction partners of the protons (fig. 13).

A structured photoresist layer 17' is then applied to the conductive layer 18. The photoresist layer 17' covers both sub-pixel areas 3, while the conductive layer 18 is freely accessible in the other sub-pixel area 3 (fig. 14).

A conversion layer 19 is then deposited by means of an electrophoretic process in the region of free access to the conductive layer 18 (fig. 15). For the electrophoretic process, electrically conductive layers 18 (not shown) are contacted at the sides of the semiconductor body 1, respectively.

In a next step, the photoresist layer 17' is removed again (fig. 16). Now, a conversion layer 19 is arranged on the radiation exit face 9 of one of the sub-pixel regions 3, while the other sub-pixel region 3 has no conversion layer 19 (fig. 16).

Now, a photoresist layer 17' is again applied, which covers the conversion layer 19 already applied and one of the directly adjacent sub-pixel regions 3. Only one sub-pixel region 3 is freely accessible (fig. 16).

The electrophoretic process is then repeated in order to deposit a further conversion layer 19' (fig. 18) on the conductive layer 18 above the radiation exit face 9 of the freely accessible sub-pixel region 3.

In a further step, the photoresist layer 17' is first removed and the semiconductor body 1 is then introduced into the reaction partners of the protons, so that the conductive layer 18 is also converted into a salt and subsequently washed out (fig. 19).

The present patent application claims priority from the german patent application DE 202013109031.1, the contents of which are hereby incorporated by reference.

The invention is not restricted by the description according to the embodiments. Rather, the invention encompasses any novel feature and any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or this combination itself is not specified in detail in the patent claims or exemplary embodiments.

As can be seen from the above description, the embodiments of the present invention cover, but are not limited to, the following technical solutions:

scheme 1. a method for producing an optoelectronic semiconductor chip, having the following steps:

-providing a semiconductor body having a pixel region with at least two different sub-pixel regions,

applying an electrically conductive layer onto the radiation exit face of at least one sub-pixel region, wherein the electrically conductive layer is adapted to at least partially constitute a salt with a reaction partner of protons,

-depositing a conversion layer on the conductive layer by an electrophoretic process.

Scheme 2. the method according to the previous scheme,

wherein the sub-pixel regions are electrically insulated from each other and each sub-pixel region has an active layer adapted to emit electromagnetic radiation of a first wavelength range.

Scheme 3. the method according to any of the above schemes,

wherein

The radiation exit face of each sub-pixel region is electrically conductive, and

-the sub-pixel regions with the conversion layer applied thereon are energized independently of the other sub-pixel regions in the electrophoretic process.

Scheme 4. the method according to any one of schemes 1 to 2,

wherein

The radiation exit face of each sub-pixel area is constructed to be electrically conductive,

the conductive layer is applied over the entire surface of the front side of the semiconductor body,

-applying a photoresist layer onto the conductive layer in at least one sub-pixel area, while the conductive layer is freely accessible in another sub-pixel area.

Scheme 5. the method according to any one of schemes 3 to 4,

wherein the conductive radiation exit face of the sub-pixel area is formed by a transparent conductive layer having a TCO material.

Scheme 6. the method according to any one of schemes 3 to 4,

wherein the electrically conductive radiation exit face is produced by removing a passivation layer applied on the sub-pixel region.

Scheme 7. the method according to any one of schemes 1 to 2,

wherein

The radiation exit face of each sub-pixel region is formed by a passivation layer,

Scheme 8. the method according to any one of schemes 4 to 7,

wherein the conductive layer is electrically contacted laterally during the electrophoresis process.

Scheme 9. the method according to any one of schemes 1 to 2,

wherein

-wherein the passivation layer is removed in the region of the radiation exit face of at least one sub-pixel region, such that the radiation exit face of the sub-pixel region is configured to be electrically conductive, while the passivation layer remains in at least one sub-pixel region.

Scheme 10. the method according to the previous scheme,

wherein

-removing the passivation layer in a further sub-pixel region such that the radiation exit face of the sub-pixel region is electrically conductive,

-applying said conductive layer onto said radiation exit face of the sub-pixel area,

-depositing a further conversion layer on the conductive layer by an electrophoretic process.

Scheme 11. the method according to any of the above schemes,

wherein the pixel region has exactly three sub-pixel regions respectively

The first sub-pixel area remains free of conversion layer,

-the second sub-pixel region is provided with said conversion layer, which conversion layer is adapted to convert radiation of the first wavelength range into radiation of the second wavelength range, and

-a third sub-pixel region is provided with a further conversion layer adapted to convert radiation of the first wavelength range into radiation of a third wavelength range different from the first and second wavelength ranges.

Scheme 12. the method according to any of the above schemes,

wherein the first wavelength range has blue light, the second wavelength range has green light, and the third wavelength range has red light.

Scheme 13. according to the method of any of the above schemes,

wherein at least the electrically conductive layer is incorporated into the reaction partners of the protons, such that the electrically conductive layer at least partially forms a salt with the reaction partners of the protons.

Scheme 14. the method according to the previous scheme,

wherein the salt is at least partially washed out of the semiconductor chip.

Scheme 15. the method according to any of the above schemes,

wherein the conductive layer has one of the following materials: lithium, sodium, potassium, rubidium, cesium, beryllium, calcium, magnesium, strontium, barium, scandium, titanium, aluminum, silicon, gallium, tin, zirconium, zinc oxide, zinc sulfide, zinc selenide, zinc telluride, and tin oxide.

Claims

1. A method for producing an optoelectronic semiconductor chip, having the following steps:

-providing a semiconductor body (1) with a pixel region (2) having at least two different sub-pixel regions (3),

-applying an electrically conductive layer (18) onto a radiation exit face (9) of at least one sub-pixel region (3), wherein the electrically conductive layer (18) is adapted to at least partially constitute a salt with a reaction partner of protons,

-depositing a conversion layer (19, 19') on the conductive layer (18) by an electrophoretic process, wherein the electrophoretically deposited layer has pores.

2. A method for producing an optoelectronic semiconductor chip, having the following steps:

-depositing a conversion layer (19, 19') on the conductive layer (18) by an electrophoretic process, wherein

-the radiation exit face (9) of each sub-pixel region (3) is electrically conductive and

-the sub-pixel regions (3) with the conversion layers (19, 19') applied thereon are energized independently of the other sub-pixel regions (3) in the electrophoretic process,

-the electrically conductive radiation exit face (9) is produced by removing a passivation layer (10) applied on the sub-pixel region (3).

3. The method according to claim 1 or 2,

wherein the sub-pixel regions (3) are electrically insulated from one another and each sub-pixel region (3) has an active layer (5) which is suitable for emitting electromagnetic radiation in a first wavelength range.

4. The method according to claim 1 or 2,

wherein the conductive radiation exit face (9) of the sub-pixel region (3) is formed by a transparent conductive layer (13) having a TCO material.

5. The method according to claim 1 or 2,

wherein

-the radiation exit face (9) of each sub-pixel region (3) is constructed to be electrically conductive,

-the conductive layer (18) is applied over the entire surface of the front side of the semiconductor body (1),

-applying a photoresist layer (17, 17') onto said conductive layer (18) in at least one sub-pixel region (3), while said conductive layer (18) is freely accessible in another sub-pixel region (3).

6. The method according to claim 1 or 2,

wherein the conductive layer (18) is electrically contacted laterally during the electrophoresis process.

7. The method according to claim 1 or 2,

wherein

-the radiation exit face (9) of each sub-pixel region (3) is formed by a passivation layer (10), and

-removing the passivation layer (10) in the region of the radiation exit face (9) of at least one sub-pixel region (3) such that the radiation exit face (9) of the sub-pixel region (3) is configured to be electrically conductive, while the passivation layer (10) remains in at least one sub-pixel region (3).

8. The method of claim 7, wherein the first and second light sources are selected from the group consisting of,

wherein

-removing the passivation layer (10) in a further sub-pixel region (3) such that the radiation exit face (9) of the sub-pixel region (3) is electrically conductive,

-applying said conductive layer (18) onto said radiation exit face (9) of the sub-pixel region (3),

-depositing a further conversion layer (19, 19') on the conductive layer (18) by an electrophoretic process.

9. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein

-the radiation exit face (9) of each sub-pixel region (3) is formed by a passivation layer (10),

10. The method according to claim 1 or 2,

wherein at least the electrically conductive layer (18) is introduced into the reaction partners of the protons, such that the electrically conductive layer (18) at least partially forms a salt with the reaction partners of the protons.

11. The method of claim 10, wherein the first and second light sources are selected from the group consisting of,

wherein the salt is at least partially washed out of the semiconductor chip.

12. The method according to claim 1 or 2,

wherein the electrically conductive layer (18) has one of the following materials: lithium, sodium, potassium, rubidium, cesium, beryllium, calcium, magnesium, strontium, barium, scandium, titanium, aluminum, silicon, gallium, tin, zirconium, zinc oxide, zinc sulfide, zinc selenide, zinc telluride, and tin oxide.

13. A method for producing an optoelectronic semiconductor chip, having the following steps:

14. A method for producing an optoelectronic semiconductor chip, having the following steps:

-the sub-pixel regions (3) with the conversion layers (19, 19') applied thereon are energized independently of the other sub-pixel regions (3) in the electrophoretic process, wherein

15. A method for producing an optoelectronic semiconductor chip, having the following steps:

-the sub-pixel regions (3) with the conversion layers (19, 19') applied thereon are energized independently of the other sub-pixel regions (3) in the electrophoretic process, and